1. wk 2 fundamentals of X-Ray physics Flashcards
___ is the smallest quantity of electromagnetic NRG
photon
___: radiation that has enough NRG to eject e- from electrically neutral atoms, leaving a charged atom
Ionization radiation
What is the difference btw x-rays and gamma rays
x ray- produced in the e- cloud of artifically excited atoms
gamma- produced inside the nucleus of radioactive atoms
how are x rays produced
in an e- cloud of artifically excited atoms
gamma- radioactive atoms
how are gamma rays produced
inside the nucleus of radioactive atoms
xray: artifically excited
(4) sources of naturally occuring enviro radiation
radon
cosmic rays
terrestrial radiation
deposited radionucleotides
**What are three sources of man-made radiation
medical x-rays
nuclear medicine
consumer products
photons travel at the speed of ___
light
(6) characteristics of a photon
- no mass
- travel at the speed of light ( c)
- have variable wavelengths/ freq
- NRG and freq are directly proportional
- electrically neutral
- inverse square law
1st rule of radiation
ALARA
as low as reaasonably achievable
what does ALARA mean
as low as reasonably acheivable
4 ways to maintain safe radiation exposure
filtration
collimation
protective apparel
protective barriers
____ are inserted into the x ray machine in order to absorb low NRG x rays (filtration)
metal filters
Low NRG x ray is ____!
garbage
- does not penetrate the PT
high NRG x rays go through the pt and produce ____
shadows
____: method of restricting the x ray beam to the part of the body of interest
collimation
- also increases the image quality
_____ are used by pt and techs to reduce unwanted exposer
lead-lined shields/ aprons
____ are xray videos
fluoroscopy
Units: (R)
roentgen
- unit of radiation exposure
- most x ray images are in (mR) 1mR= 0.001R
Units: (rad)
radiation absorbed dose
units: (rem)
equivalent dose
Units: (LET)
linear energy transfer
___: unit of radiation exposure. measures the ability ot ionize air
roentgen ( R)
SI units of ( R)
air kerma (Gya) 1R= 0.01 Gya 0.00001= 10^-5Gya
Air kerma is the SI unit for ___
Roentgen ( R)
1R= 0.01Gya
___: is a measurement of the amt of radiation deposited into a mass (soft tis)
Adsorbed Dose (rad)
SI unit of absorbed dose (rad)
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